diff options
| -rw-r--r-- | drivers/spi/spi.c | 91 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 36 |
2 files changed, 127 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 47eff8012a77..894ed0357dd7 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1024,6 +1024,8 @@ out: if (msg->status && master->handle_err) master->handle_err(master, msg); + spi_res_release(master, msg); + spi_finalize_current_message(master); return ret; @@ -2013,6 +2015,95 @@ struct spi_master *spi_busnum_to_master(u16 bus_num) } EXPORT_SYMBOL_GPL(spi_busnum_to_master); +/*-------------------------------------------------------------------------*/ + +/* Core methods for SPI resource management */ + +/** + * spi_res_alloc - allocate a spi resource that is life-cycle managed + * during the processing of a spi_message while using + * spi_transfer_one + * @spi: the spi device for which we allocate memory + * @release: the release code to execute for this resource + * @size: size to alloc and return + * @gfp: GFP allocation flags + * + * Return: the pointer to the allocated data + * + * This may get enhanced in the future to allocate from a memory pool + * of the @spi_device or @spi_master to avoid repeated allocations. + */ +void *spi_res_alloc(struct spi_device *spi, + spi_res_release_t release, + size_t size, gfp_t gfp) +{ + struct spi_res *sres; + + sres = kzalloc(sizeof(*sres) + size, gfp); + if (!sres) + return NULL; + + INIT_LIST_HEAD(&sres->entry); + sres->release = release; + + return sres->data; +} +EXPORT_SYMBOL_GPL(spi_res_alloc); + +/** + * spi_res_free - free an spi resource + * @res: pointer to the custom data of a resource + * + */ +void spi_res_free(void *res) +{ + struct spi_res *sres = container_of(res, struct spi_res, data); + + if (!res) + return; + + WARN_ON(!list_empty(&sres->entry)); + kfree(sres); +} +EXPORT_SYMBOL_GPL(spi_res_free); + +/** + * spi_res_add - add a spi_res to the spi_message + * @message: the spi message + * @res: the spi_resource + */ +void spi_res_add(struct spi_message *message, void *res) +{ + struct spi_res *sres = container_of(res, struct spi_res, data); + + WARN_ON(!list_empty(&sres->entry)); + list_add_tail(&sres->entry, &message->resources); +} +EXPORT_SYMBOL_GPL(spi_res_add); + +/** + * spi_res_release - release all spi resources for this message + * @master: the @spi_master + * @message: the @spi_message + */ +void spi_res_release(struct spi_master *master, + struct spi_message *message) +{ + struct spi_res *res; + + while (!list_empty(&message->resources)) { + res = list_last_entry(&message->resources, + struct spi_res, entry); + + if (res->release) + res->release(master, message, res->data); + + list_del(&res->entry); + + kfree(res); + } +} +EXPORT_SYMBOL_GPL(spi_res_release); /*-------------------------------------------------------------------------*/ diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 53be3a4c60cb..38204b584dc5 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -582,6 +582,37 @@ extern void spi_unregister_master(struct spi_master *master); extern struct spi_master *spi_busnum_to_master(u16 busnum); +/* + * SPI resource management while processing a SPI message + */ + +/** + * struct spi_res - spi resource management structure + * @entry: list entry + * @release: release code called prior to freeing this resource + * @data: extra data allocated for the specific use-case + * + * this is based on ideas from devres, but focused on life-cycle + * management during spi_message processing + */ +typedef void (*spi_res_release_t)(struct spi_master *master, + struct spi_message *msg, + void *res); +struct spi_res { + struct list_head entry; + spi_res_release_t release; + unsigned long long data[]; /* guarantee ull alignment */ +}; + +extern void *spi_res_alloc(struct spi_device *spi, + spi_res_release_t release, + size_t size, gfp_t gfp); +extern void spi_res_add(struct spi_message *message, void *res); +extern void spi_res_free(void *res); + +extern void spi_res_release(struct spi_master *master, + struct spi_message *message); + /*---------------------------------------------------------------------------*/ /* @@ -720,6 +751,7 @@ struct spi_transfer { * @status: zero for success, else negative errno * @queue: for use by whichever driver currently owns the message * @state: for use by whichever driver currently owns the message + * @resources: for resource management when the spi message is processed * * A @spi_message is used to execute an atomic sequence of data transfers, * each represented by a struct spi_transfer. The sequence is "atomic" @@ -766,11 +798,15 @@ struct spi_message { */ struct list_head queue; void *state; + + /* list of spi_res reources when the spi message is processed */ + struct list_head resources; }; static inline void spi_message_init_no_memset(struct spi_message *m) { INIT_LIST_HEAD(&m->transfers); + INIT_LIST_HEAD(&m->resources); } static inline void spi_message_init(struct spi_message *m) |